This document discusses the anatomical basis of biomechanics. It begins by defining biomechanics and its two main components - kinetics and kinematics. It then discusses the five main components of biomechanics: force, motion, momentum, balance, and lever. The document outlines the history of biomechanics beginning with Aristotle and continuing through modern scientists like Galileo and Borelli. It defines important anatomical terms like planes, axes, and directional terms. It also discusses levers and their three positions. Finally, it covers properties of skeletal muscle like irritability, contractility, and elasticity as well as their main functions in producing movement, maintaining posture, and stabilizing joints.

1. ANATOMICAL BASIS OF
BIOMECHANICS
OBAJE GODWIN SUNDAY
ALEX EKWUEME FEDERAL UNIVERSITY
NDUFU ALIKE IKWO EBONYI STATE,
NIGERIA, +2348068638121

2. Introduction
• Bio-mechanics means two words as in,
bio (living beings) while mechanics is
branch of physics involving analysis of
the actions of forces and motion
• It is application of mechanical laws on
living beings, specifically the locomotive
systems of the body

3. Mechanics
• Study of mechanics in the human body
divides into 2 parts/areas as follows:
• Kinetics- forces producing motion
(muscles, gravity)
• Kinematics- the general description of
motion like; location, bone motion and
trajectory

4. But do we need biomechanics?
Yes!
• In community health, it is important to
get people to move correctly for better
health relation
• To improve performance
• To support disabilities
• Multitude of jobs

5. In the 21th Century, what
biomechanics is……
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6. History
• 1st biomechanician in modern science
today is the late Aristotle

7. History
• • Leonardo da Vinci-The famous artist,
but worked mostly as an engineer
• He analyzed muscle forces as acting
along lines connecting origins and
insertions and studied joint function

8. History
• Flemish physician Andreas Vesalius
published his beautifully illustrated text,
On the Structure of the Human Body
• Galileo Galilee-He was particularly aware
of the mechanical aspects of bone
structure and the basic principles of
allometry

9. History
• Marcello Malpighi- Introduced the levers
of skeletal system of body and its motion
• He had intuitive understanding of static
equilibrium of human body
• He determined the position of the
human center of gravity

10. History
• Borelli- contributed significantly to
astronomy
• He pioneered the motion analysis of
biomechanics
• This genealogy is ended with 20th
century. Now we could move on to 21st
century

11. So, what are the components of
biomechanics?
There are 5 main components as follows:
• Force
• Motion
• Momentum
• Balance
• Lever

12. Plane and axis
What is plane?
• Is the surface on which movement occurs or
takes place.
• Any movement occurs in a plane around an axis
• Axis of the same plane makes an angle
perpendicular to that plane.
What is axis?
• Is the line around which movement takes place
• Axis is the singular and axes are the plural noun

13. Directional terms in anatomy
• SUPERIOR – Directed upwards or towards
the head
• INFERIOR – Directed downwards or
towards the feet
• ANTERIOR – Directed towards the front
of the body
• POSTERIOR – Directed towards the back
of the body
• MEDIAL – Nearer the midline of the body

14. Directional terms in anatomy

15. Directional terms in anatomy
• LATERAL – Farther from the midline of the
body
• PROXIMAL – Nearer to the attachment of a
limb to the trunk
• DISTAL – Farther from the attachment of the
limb to the trunk
• SUPERFICIAL – Located on or near the surface
of the body
• DEEP – Away from the surface of the body

16. Anatomical positions and terms
• Cardinal plane-imaginary perpendicular
reference planes that divide the body in
half by mass of axial skeleton
• Parallel Plane-imaginary surface where
the movement of appendicular skeleton
take place

17. Anatomical positions and terms
• Diagonal plane-plane other than cardinal or
parallel planes, Where movement occurs in a
diagonal pattern

18. Anatomical positions and terms
• Sagittal – Divides the body into left and
right halves
• Frontal – Divides the body into front and
back halves
• Transverse – Divides the body into top
and bottom halves

19. Anatomical positions and terms
• Segmental – Flexion – Extension –
Hyperextension – Dorsiflexion Ankle –
Plantar flexion
• Segmental – Abduction – Adduction – Lateral
flexion – Elevation and depression of the
shoulder girdle (or scapula) – Upward and
downward rotation of the shoulder girdle (or
scapula) – Radial deviation – Ulnar deviation
Wrist

20. Anatomical positions and terms
• Segmental – Supination - forearm –
Pronation – forearm – Horizontal
abduction (transverse flexion) –
Horizontal adduction (transverse
extension)
• Pronation of subtalar joint – abduction +
eversion– Supination of subtalar joint –
adduction + inversion

21. Levers
• The lever helps the body to overcome a
force greater than the effort used e.g. a
crowbar / a calf raise or move something
a greater distance e.g. an over-arm throw
• Consists of fulcrum (pivot point) – Load –
could be gravity, body weight and effort –
provided by muscular contractions

22. Levers perform two main functions
• To increase the resistance(or force) that
can be moved with a given effort e.g. a
crowbar
• To increase the velocity at which an
object will move with a given force. E.g. A
golf club.

23. For instance,
Sporting levers in,
• Golf clubs are selected according to
length – a longer club will produce a
longer lever and will send the ball further
• A defender in hockey will use a heavier
stick
• An overarm serves in tennis makes the
most use of the power by making the
lever as long as possible

24. Lever positions
First Order Lever
• The fulcrum is in the middle
• The load is at one end and the effort
applied at the other
• Example in the body = Joint at the neck

25. Lever positions
Second Order Lever
• The Load is in the middle
• The fulcrum is at one end, the effort applied
at the other Example in the body = The ankle
joint

26. Lever positions
Third Order Lever
The effort is in the middle
The load is at one end, the fulcrum at the other
Example in the body = most of our skeletal
muscles

27. Before looking at sport & movement,
We must understand FORCE properly.
• A force is a push or pull that alters or
tends to alter the state of motion of a
body
• For example, taking a football penalty,
returning a tennis, a sprint finish, and
jumping on a trampoline

28. Before looking at sport & movement,

29. Before looking at sport & movement,
Application of force causes;
• LINEAR MOTION
If a force is applied forward
• ANGULAR MOTION
If a force is applied at the center it will
cause spin

30. Before looking at sport & movement,
GENERAL MOTION
• Many sporting examples are a combination of
both angular and linear motion
• The upper body shows linear motion
• The legs show angular motion

31. Before looking at sport & movement,

32. Don’t forget, you cant discuss force
Without the applications of Newton’s laws
• A body continues in a state of rest or of
uniform velocity unless acted upon by an
external force (FIRST LAW)

33. Don’t forget, you cant discuss force
• When a force acts on an object, the rate
of change of momentum experienced by
the object is proportional to the size of
the force and takes place in the direction
in which the force acts (SECOND LAW)
• For every action there is an equal and
opposite reaction (THIRD LAW)

34. Don’t forget, you cant discuss force

35. ASSIGNMENT
Could you explain how forces are applied
to
• Cause something to move
• Change direction
• Accelerate

36. ASSIGNMENT
From the links below, discuss the following
1. Muscle mechanics
2. Levers in biomechanics
3. Pattern of walking in biomechanics
4. Knowledge of anthropometric studies in
biomechanics
• https://www.physio-pedia.com/Muscle_Biomechanics
• https://www.youtube.com/watch?v=V1NC5wOg0TM
• https://www.menshealth.com/fitness/a37272280/anth
ropometry-body-types-workouts/

37. MUSCULAR CONSIDERATION IN
BIOMECHANICS
Why considering the muscles in biomechanics?
Any discussion of shoulder pathologies
must start with a solid understanding of
the anatomical and biomechanical
challenges in this area.

38. For instance,
• Scapula being surrounded by about 20
muscles
• Threadmill vs bike: Which offers better
cardio work?

39. Properties,
functions, and roles
of skeletal muscle

40. MUSCLE TISSUE PROPERTIES

41. Irritability or excitability
• Is the ability to respond to stimulation
• In a muscle, the stimulation is provided
by a motor neuron releasing a chemical
neurotransmitter
• Skeletal muscle tissue is one of the most
sensitive and responsive tissues in the
body.

42. Contractility
• Is the ability of a muscle to generate
tension and shorten when it receives
sufficient stimulation
• Some skeletal muscles can shorten as
much as 50% to 70% of their resting
length
• The average range is about 57% of
resting length for all skeletal muscles

43. Extensibility
• Is the muscle’s ability to lengthen, or
stretch beyond the resting length
• The skeletal muscle itself cannot produce
the elongation
• Another muscle or an external force is
required.

44. Elasticity
• Is the ability of muscle fiber to return to
its resting length after the stretch is
removed
• The properties of elasticity and
extensibility are protective mechanisms
that maintain the integrity and basic
length of the muscle.

45. FUNCTIONS
PRODUCE MOVEMENT
• Skeletal movement is created as muscle
actions generate tensions that are
transferred to the bone
• The resulting movements are necessary
for locomotion and other segmental
manipulations

46. FUNCTIONS
MAINTAIN POSTURES AND POSITIONS
• Muscle actions of a lesser magnitude are
used to maintain postures
• This muscle activity is continuous and
results in small adjustments as the head
is maintained in position and the body
weight is balanced over the feet

47. FUNCTIONS
STABILIZE JOINTS
• Muscle actions also contribute
significantly to stability of the joints
• Muscle tensions are generated and
applied across the joints via the tendons,
providing stability where they cross the
joint

48. FUNCTIONS
OTHER FUNCTIONS
• The skeletal muscles also provide other
functions that are not directly related to
human movement
• Muscles support and protect the visceral
organs and protect the internal tissues from
injury
• Tension in the muscle tissue can alter and
control pressures within the cavities